通常，女性在怀孕一定时间后，会去医院进行胎位检查，从检查出来的胎位图中，孕妈妈能及时了解宝宝在母体中的位置。通过胎位图，医生也能判断胎儿的位置是否正常。那么，孕期宝宝有哪些胎位呢？

01 Anterior position 枕前位

The best position for the fetus to be in before childbirth is the anterior position. The majority of fetuses get into this position before labor begins.

枕前位是最正常最适合自然分娩的胎位，绝大多数的胎儿会在分娩前自动进入这种姿势。

This position means the fetus's head is down in the pelvis, facing the woman's back. The fetus's back will be facing the woman's belly.

这种胎位下胎儿的头朝下，在骨盆入口的部位。胎儿的背朝向妈妈的腹部。

This position means the fetus's head can be tucked in, allowing the top of it to press down on the cervix, which encourages it to open during labor.

这种姿势下胎头可以挤压宫颈，促使其张开。

A doctor or midwife may describe a fetus that lies slightly to the left as left occiput anterior or LOA, and one that lies slightly to the right as right occiput anterior or ROA.

枕前位还包括左枕前位（LOA）和右枕前位（ROA），其中左枕前位是最常见的胎位。

02 Posterior position 枕后位

The posterior position is also known as the back-to-back position. This is where the fetus's head is pointing down, and their back is resting against the woman's back.

枕后位也被人叫做“背靠背”。和枕前位一样，宝宝的头是朝下的，但背部朝向妈妈的背部。

In this position, it can be difficult for the fetus to tuck their head in, which can make passing through the smallest part of the pelvis more challenging. This can lead to a slower and longer labor than the anterior position, and may also cause a backache.

这种胎位多发生于骨盆又轻度狭窄的情况下，影响胎头的下降。相比于枕前位，枕后位的产程可能更长，还可能导致腰背痛。

03 Transverse lie position 横位

A transverse lie position is when the fetus is lying horizontally in the uterus. Most fetuses will not remain in this position in the weeks and days leading up to labor.

胎儿横位下，胎体纵轴与母体纵轴成直角。绝大多数的胎儿并不会一直保持这种姿势。

If a fetus is still in the transverse lie position just before birth, a cesarean delivery will be necessary.

横位是很危险的胎位，如果临产前还是胎儿横位，就必须采取剖宫产。

Without a cesarean delivery, there is a risk of a medical emergency known as an umbilical cord prolapse.

横位如果没有及时处理，会有脐带脱垂的风险。

04 Breech position 臀位

The breech position is when the fetus remains with the head up instead of down in the woman's pelvis. There are different types of breech position, including:

臀位的胎儿头朝上，而不是向下朝着妈妈的骨盆。臀位又可分为三类：

Complete breech: In this position, the fetus "sits" with their legs crossed in front of the body, so the feet are near their buttocks.

完全臀：胎儿双髋关节及膝关节屈曲，犹如盘膝而坐，以臀部和双足为先露部。

Frank breech: In this position, the fetus's legs lie straight upward in front of their body, so the feet are near the face.

单臀：胎儿双髓关节屈曲，双膝关节伸直，以臀部为先露部。

Footling breech: In this position, the fetus has either one or both feet hanging below their bottom. If a woman gave birth vaginally, one or both feet would come out first.

不完全臀：胎儿以一足或双足、一膝或双膝，或一足一膝为先露部位。

If a woman is carrying twins, one fetus may be in an anterior or posterior position while the other fetus is in a breech position.

如果怀了双胞胎，很可能是一个宝宝是枕前位，另一个就是臀位。

Takeaway

写在最后

A baby will move into many different positions throughout pregnancy. During the last few weeks of pregnancy, most babies move into an anterior position, which is the best position for vaginal birth.

不同的孕育阶段，胎儿在母体内的位置是不一样的。孕晚期，绝大多数的胎儿会转化为枕前位，最有有利于阴道分娩。

If a baby is still in a transverse lie or breech position just before labor, a doctor or midwife will make medical interventions to ensure the safety of the woman and baby during childbirth.

如果临产前胎儿还是处于横位或者臀位，医生会行使外倒转术改变胎位，来保证分娩时胎儿和母体的安全。